Remove group-by since that's been covered

trptcolin · trptcolin · commit 72af893f8fea · 2014-01-21T08:35:54.000-06:00
diff --git a/ideaboard.txt b/ideaboard.txt
@@ -21,7 +21,6 @@ flatten
 
 frequencies
 reductions
-group-by
 keep
 keep-indexed
 map-indexed
